Siemens SIMATIC OpenPCS 7, Function Manual

Page: 4 / 96

6 OpenPCS 7 interface..................................................................................................................................45
6.1 Access options............................................................................................................................45
6.2 Data transmission........................................................................................................................45
6.3 OPC Data Access (OPC DA)......................................................................................................46
6.3.1 Overview......................................................................................................................................46
6.3.2 Introduction to the OPC Data Access interface...........................................................................46
6.3.3 How the OPC DA server works...................................................................................................47
6.4 OPC Historical Data Access (OPC HDA)....................................................................................48
6.4.1 Overview......................................................................................................................................48
6.4.2 How the OPC HDA server works.................................................................................................48
6.4.3 Data structure of the OPC HDA server........................................................................................49
6.4.4 Overview of supported attributes.................................................................................................50
6.4.5 Overview of supported aggregate functions................................................................................50
6.4.6 Overview of supported functions.................................................................................................51
6.4.7 Time format of the OPC HDA server...........................................................................................52
6.4.8 Quality codes of the OPC HDA server........................................................................................54
6.4.9 Write access supported by the OPC HDA server........................................................................54
6.5 OPC Alarms and Events (OPC A&E)..........................................................................................55
6.5.1 Overview......................................................................................................................................55
6.5.2 Introduction to OPC A&E.............................................................................................................55
6.5.3 Mapping the PCS 7 OS message system on OPC A&E.............................................................57
6.5.4 Mapping the message classes and message types of PCS 7 OS on OPC A&E........................59
6.5.5 Mapping priorities of PCS 7 OS messages to OPC A&E............................................................59
6.5.6 Attributes of the PCS 7 OS message system..............................................................................60
6.5.7 Acknowledgment concept............................................................................................................61
6.5.8 Quality codes for OPC A&E.........................................................................................................64
6.5.9 OPC A&E with hierarchical access..............................................................................................64
6.5.9.1 Differences between OPC A&E and OPC A&E with hierarchical access....................................64
6.5.9.2 Example 1: Messages are not assigned to any area...................................................................66
6.5.9.3 Example 2: Messages are assigned to an area..........................................................................69
6.5.9.4 Example 3: Messages of an area are assigned to an alarm hiding group..................................71
6.5.10 Upgrading with OPC A&E............................................................................................................73
6.5.10.1 Updating PCS 7 projects with OPC A&E.....................................................................................73
6.5.10.2 How to update an OPC project with PCS 7 V8.0.........................................................................73
6.6 OPC Historical Alarms and Events (OPC "H" A&E)....................................................................74
6.6.1 Overview......................................................................................................................................74
6.6.2 Introduction to OPC "H" A&E.......................................................................................................75
6.6.3 Reading archived messages.......................................................................................................75
6.6.4 Syntax for access to archived messages....................................................................................76
6.6.5 Read modes for archived messages...........................................................................................78
6.6.6 Identifying archived messages....................................................................................................79
6.7 OLE DB.......................................................................................................................................80
6.7.1 Overview......................................................................................................................................80
6.7.2 Basics of OLE DB........................................................................................................................81
6.7.3 Establishing the connection to the database...............................................................................82
6.7.4 Access to the OLE DB provider...................................................................................................83
6.7.5 Querying archive data.................................................................................................................85
6.7.5.1 Representation of the process value archive..............................................................................85
Table of contents
OpenPCS 7
4
Function Manual, 05/2012, A5E02780178-02